Cepheus (constellation) in the context of "Cepheus, King of Aethiopia"

Play Trivia Questions online!

or

Skip to study material about Cepheus (constellation) in the context of "Cepheus, King of Aethiopia"




⭐ Core Definition: Cepheus (constellation)

Cepheus is a constellation in the deep northern sky, named after Cepheus, a king of Aethiopia in Greek mythology. It is one of the 48 constellations listed by the second century astronomer Ptolemy, and it remains one of the 88 constellations in the modern times.

The constellation's brightest star is Alderamin (Alpha Cephei), with an apparent magnitude of 2.5. Delta Cephei is the prototype of an important class of star known as a Cepheid variable. RW Cephei, an orange hypergiant, together with the red supergiants Mu Cephei, MY Cephei, VV Cephei, V381 Cephei, and V354 Cephei are among the largest stars known. In addition, Cepheus also has the hyperluminous quasar S5 0014+81, which hosts an ultramassive black hole in its core, reported at 40 billion solar masses, about 10,000 times more massive than the central black hole of the Milky Way, making this among the most massive black holes currently known.

↓ Menu

In this Dossier

Cepheus (constellation) in the context of Orbital pole

An orbital pole is either point at the ends of the orbital normal, an imaginary line segment that runs through a focus of an orbit (of a revolving body like a planet, moon or satellite) and is perpendicular (or normal) to the orbital plane. Projected onto the celestial sphere, orbital poles are similar in concept to celestial poles, but are based on the body's orbit instead of its equator.

The north orbital pole of a revolving body is defined by the right-hand rule. If the fingers of the right hand are curved along the direction of orbital motion, with the thumb extended and oriented to be parallel to the orbital axis, then the direction the thumb points is defined to be the orbital north.

↑ Return to Menu

Cepheus (constellation) in the context of Γ Cephei

Gamma Cephei (γ Cephei, abbreviated Gamma Cep, γ Cep) is a binary star system approximately 45 light-years away in the northern constellation of Cepheus. The primary (designated Gamma Cephei A, officially named Errai /ɛˈr./, the traditional name of the system) is a stellar class K1 orange giant or subgiant star; it has a red dwarf companion (Gamma Cephei B). An exoplanet (designated Gamma Cephei Ab, later named Tadmor) has been confirmed to be orbiting the primary.

Gamma Cephei is the naked-eye star that will succeed Polaris as the Earth's northern pole star, due to axial precession. It will be closer to the northern celestial pole than Polaris around 3157 CE and will make its closest approach around 4094 CE. The 'title' will pass to Iota Cephei some time around 5200 CE.

↑ Return to Menu